En route to visit friends over in Walthamstow, via Coppermill Lane and thus past the Filter Beds and the southern fringe of Walthamstow Reservoirs; the former clouded with at least 200 Sand Martins, and the latter with the requisite goose flock. Greylags, Canadas, and.... a Barnacle!
The chances of it having just arrived from the arctic tundra are about as likely as TMS not being the greatest entertainment known to humankind, but it's unringed, and so I recommend a mass twitch just in case.
